Piston resizer



w. c. WALKER P'IsT'oN Riz-:Smm

June 26, 1 928.

Filed Nov. 9, 1926 /NVE/vvTo/e miliam OAD ciUCeP da ATTO/Nans Patented June 26, 1928.

UNITED: STATES WILLIAM CLARENCE WALKER, on TULsA, OKLAHOMA.

"risfron RnsIzEn.

Application filed November 9,1%?26.` Serial No. 147,367

My 'invention relates to devices for resizing pistons of the lsplit skirt type of construction beyond their original sizes,`and it consists in the combinations, constructions and arrangements herein describedl andclaimed. Y

lArn object of the invention is the provision ofv a resizer which can be conveniently and easily operated to resize a 'pistonofthey type referred to as desired within a considerable range of expansion. i f f 'A further ob'ect of the invention lis the provision of a piston resizer that is simple in construction, reliable in use, not likely to get out of order easily andy thoroughly practical commercially. i

A still further object of the invention `is the provision of a novel method of treating an expanded piston to assure accuracy of' size of the piston when it has set to a predetermined extent;

Other objects and advantages of the invention will be apparent from the following description, considered in' conjunction with the accompanying drawings, forminga part. of this application, in whichz- Figure l is' a viewof the 11n-proved piston resizer partly in side elevation and partly inl vertical section, Vshowing the contracted" position of the device in full lines` and showing in dotted lines Van expanded' position of the device,

Figure 2 Figures d and 5 are perspective views of modified forms ofk resizer arms and heads which may be used in the improved resizeig* the modifiedforms of the res1zer' portions of arms being broken vaway andotherportion-s being shown in section.

Referring now to the drawings, it will be observed that the improved resizer has a body l which may beformed of any suitable metal, such ass'teehand may be of block form as shown. The body l is adapted-to be disposedV transversely in the bore of the hollow body of a conventional piston V(not shown) and the body 1 is provided with a transverse bore 2, the center line of which preferably is coincident with the transverse is a bottom plan view of the structure exhibited in Figure l, fther full median line ofthebody l. The body'l also is formed with a longitudinal bore 3 which intersects the bore 2 and which may extend longitudinally of the body l nearer to one face of the body than to the opposite face of? the body as clearly shown in vFigure 1. The opposite end portions ofthe bore 3 constituteguide passages for longitudinally slidable'ry arms 4 which are of sufficient length to abut each other in the bore .2'

when the oulterends ofthe resizer arms 4 are substantially flush with the end walls of thebody l as shown in Figure 2. Resizer heads 5, each of which preferably is a Vsegment of -a lcylinder and has its outer face curved convexly in onel plane `to con'- form to the curvaturefof the inner wall of a piston with which the device is to be usedl, are secured to the outer ends of the arms 2t by screws 6; The screws G-have their heads conntersun-k inthe onter faces of the resizer heads 5. When the inner faces of the resizerv heads 5 are conc-avely curved to be parallel with the outer faces ofthe resizer heads as shownl in the drawings, the end walls of the body 1 preferably will be convexly curved also to conform-to the:curvature of the in` ner faces of: the resiZerheads. i

The Vinner'endsofv the arms l have transversel'yextending grooves 7, each of said grooves decreasing inwidth and deptl'rregularly 'from one end of thefgroove to its opposite end. l u Y An expanding needle -8 hasa tapering end portion 9, the taper of whichconforms to the4 taper of the grooves.- The wall of the bore t QYi-s-provided with screw threads at l()V which extend through the relatively thick portion of the body l from one side of the bore 3 to the remote face of the body land which are adapted for engagement with screwthreads 1l. '2l-he screw threads 11 areformed on the expanding needle 8V atfthe inner end of the tapering*portion'9A of the expandingV needle.v The outerend ofthe expanding needle is` provided -vvithv a cross 'handlemember 12.

The resizer arms are ,secured tothe resizerjheads 5 so that the larger ends of the grooves wil'li be nextk to the ,extremityy of. rthe tapering portion 9 of' the expanding needle. and will partially receive the'ftapei ing end-portion 9V ofv theexpandingl needle when theresizer arms are 1in their retracted positions' asshow-n by the full lines in Fignre l', The device then'V is in its contractedpositionand may be inserted to a desirable position in a piston that is to 'beexpanded The expanding needle 8 then is screwed into the body 1 to advance the tapering portion 9 between the grooves 7 from the position shown byV the full lines in Figure 1 toward the dotted line position of Figure 1. It is obvious that the contact of the tapering end portion 9 of the expanding needle with the tapering Walls of the grooves 7 will bias vthe resizer arms outward in the guide passages and that the resizer heads will be urged against the lwall of the Vpiston to effect expansion of the piston body as desired. The initial expansion of the Vpiston by means of the device should be approximately three times the permanent expansion that is desired. That is, if the piston body is to be expanded l/5000th of an inch permanently, the expansion needle 8 should be screwed into the body until the piston ,body has been expanded 3/5000. lCylinder oil then V1s `sprayed onto the piston and the piston then is held in proximity to the Haine from a torch,-the piston being turned slowly and regularly until all `portions Aof the piston body have been subjected to the action of heat from the torch flame and until the cylinder'oil on the piston has dried.` The piston with the resizer therein is taken away from the flame and is dipped into a cold solution of water and salt. The piston and the resizer are left in the cooling solution until they have cooled, after which they are removed and the resizer is permitted to contract by manipulating the expanding needle 8 as required to permit the resizer arms 4 to move inward in theguide passages of the resizer body and when the piston body has set, the desired degree of` expansion'` will have been obtained.

Each of the resizer arms of the device may be a one-piece rod-like `member as shown in Figures 1 to 3 inclusive'or may `be a longitudinally extensible and contractile memberas shown in eachY of Figures 3 and 4. The form of resizer arms shown in Figure 3 comprises an inner end section 15 which has thc groove 7 formed in its inner end face,`and an outer end section 16 that is secured to the associated resizer head 5.V

The section 15 includes a reduced axial eX- tension 17 atfthe outer endof the secti0n15 and a shoulder-18 thus isproduced at the juncture of the section 15` and its "extension 17. The extension 17 `is adapted to tit slid-L ably, although rather tightly, in an axial socket 19 in the adjacent end portion of the section 16. One or. more spacer Washers maybe Vdisposed on the extension 17 between the shoulder 18 and the adjacent end of the section 16 and the effective length of the expander arm` shown in Figure 3j may be varied by varying the number or the size of the spacing washers that are placed on the extension 17 at a given time. For

example, I show in Figure 3 these washers respectively indicated at 20, 21 and 22. The thicknesses of these Washers vary and are known, the thickness of the washer 22 being one-half the thickness of the Washer 21 and'the Washer 21 in turn being one-half the thickness of the washer 20. The effective length of the resizer arm shown in Figure?) thus may be varied accurately and within a considerable range of adjustment by selection `of the proper spacing Washer` or washers for a desirable adjustment or adjustments. j c l The form of resizer arm shown in Figure 4 has the inner end section 25 and an outer end section 26, the` section 25 having a groove 7 in its inner end andV the section 26 being secured to the associatedresizer head 5. The section 26 has an axial socket 27 in its inner end and the section 25 is provided with an axial extension 28 which is in threaded engagement Withthe wall of the socket 27,` whereby the sections 25 and 26 can be turned relatively to each other to vary the effective length of the resizer'arms within a considerable range as desired.

Obviously, the invention is susceptible of Y embodiment in Vforms other than those which are illustrated in the accompanying drawings and I therefore consider as my own all suchmodifications and adaptations there-` of as fairly fall within the scope of the appended claims.

I claim j j i 1. A piston resizer comprising a body having a longitudinal bore and a transverse bore intersecting each other intermediate the ends of said body, said body being adapted to be disposed `transversely within the bore of a piston that is to be resizeda pair of movable resizermembers having heads at the ends ofsaid bodya-nd having armsfextending slidably in the end portions of said longitudinal bore of .the body, said arms projecting into said ,transverse bore of the body when theV arms` arein their retracted positions, and an expandingv needle adjustably engaged with the Wall of the transverse bore of the body and having an end portion ex-Y tending between the inner ends ofsaid resizer arms for urging said resizer arms outwardv when said@ expanding needle is turned in one direction while in engagement-with the wall of the transverse bore of the body.

`2. `A piston resizer comprising a body having a longitudinal bore and a transverse bore intersecting each other,` Said body lbeing adapted to be disposed transversely within the bore of a piston that is to be resized, movable resizer members having head portions at the ends of said body and having arms extendin through the end portions of the longitu inal bore ofthe body into the transverse bore of the body, an expanding needle'having a portion in threaded enltlii gagement with the wall of the transverse bore of the body and having a tapering .end portionL extending between the inner ends of said resizer arms, said resizer arms having tapering transverse grooves in their inner ends for engaging with the tapering end portion of said expanding needle.

3. A piston resizer comprising` a body having a longitudinal lbore and a transverse bore intersecting y each other, said body being adapted to be disposed transversely within the bore of a piston that is to be' resized, movable resizer members vhaving head portions at the ends of said body and having arms extending through the end portions ot' the longitudinal bore of the body into the transverse bore of the body, Van expanding needle having a portion in threaded engagement with the wall of the transverse bore of the body and having a tapering end portion extending between the inner ends of said resizer arms, said resizer arms havingv tapering transverse grooves in their inner ends for enga-ging with the tapering end portion of said expanding needle, said grooves in the inner ends of said expansion arms decreasing in width and depth in conformity with the taper of the end portion of said expand@ ing needle.

il. A piston resizer comprising body having a longitudinal bore and a transverse bore intersecting each other, said body being adapted to be disposed transversely within the bore oi' a piston that is to be resized, movable resizer members having head portions at the ends of said body and having f arms extending through the end portions oi the longitudinal bore of thebody into the transverse bore of the body, an expanding needle having a portion in threaded engagement with the wall of the transverse bore of the body and having a tapering end portion extending between the inner ends of said resizer arms, said expansion heads having their outerfaces cur-ved convexly to conform to the curvature of the inner wall of the cylinder that is to be expanded, the inner iaces of said expansion heads andthe outer end faces of said body being complementarily curved'. Y

5. A piston resizer comprising a body having a bore, resizer members comprising heads at the opposite ends of said bore and arms slidable in the opposite end portions of said l bore, means adjustably engageable with the body for urging said resizer' arms outward vin the end portions oi? said bore equally when n the arms are at the limits et their inward movements in the end portions oi' said bore,

each of said arms being longitudinally ex-v the other section having an axial extension at its outer end fitting slidably in said socket, and a plurality of spacing washers of difierent sizes adapted to be used selectively or. at the same time on said axial extensions of one of the sections of said resizer arm and between said sections ot" said resizer arm.

7 A piston resizer comprising a body having a bore, resizer members comprising heads at the opposite ends oi said bore and arms slidable in the opposite end portions of said bore, means adjustably engageabie with they body for urging said resizer arms outward in therend portions of said bore equally when each of said arms Comprising a pair.

the arms areat the limits of their inward movements in the end portions of said bore, eaolr of said arms comprising al pair `of aligned sections, one of said sections having an axial socket in its inner end andthe other section having an axial extension at its outer `end fitting slidably in said socket, and a plurality of spacing washers ot diiierent sizes' adapted-to be used selectively or at the same time on said axial extension of one of the sections oi? said resizer arm and between'said sections of said resizer arm, the wall of said axial socket and said axial extensiony having Vcoopera`ting screw threads.

WILLIAM CLARENCE l/VALKER. 

